| The formation of carbon-carbon bonds is of great importance in organic chemistry,and transition metals play important roles in the formation of carbon-carbon bonds.The Heck-type reaction is one of the most important methods for the construction of carbon-carbon bonds leading to new alkenes.However,examples of the C-H olefination,followed by cyclization with the directing groups are much less abundant.Actually,this C-H olefination and cyclization strategy is useful for the synthesis of complicated heterocycles,which makes the directed C-H olefination more fascinating.Polycyclic aromatic hydrocarbons exist widely in many nature products and some of them exhibit significantly biological and electroluminescent activities.Among many methods for the synthesis of these compounds,transition metal-catalyzed intramolecular cyclization procedures using the C-H bond functionalization strategy are very attractive.Despite these advances,examples of the intramolecular cyclization routes to the synthesis of these compounds through the C-H bonds activation are much less abundant.To the best of our knowledge,a general C-H bond functionalization protocol under transition metal-free conditions for the synthesis of polycyclic aromatic hydrocarbons has not yet been established.The two contents of the dissertation are listed as follows:1、A new,unexpected route has been developed for the synthesis of phenanthridines via Pd(Ⅱ)-catalyzed C-C bond cleavage cylization of biphenyl-2-amines with alkenes involving remote aryl C-H olefination and carboamination.In the present of PdCl2、Cu(OAc)2 and O2,a variety of biphenyl-2-amines compounds underwent the reactions with butyl acrylate to afford the corresponding phenanthridines in moderate to good yields.The mechanism was also discussed according to the present results,particularly the controlled experiments.2、The first direct intramolecular benzylation reaction of an arene C-H bond with tosylhydrazones by ’BuONa-mediated reductive coupling process has been reported preliminary.This method displayed high generality:it allows a wide range of N-tosylhydrazones for the construction of numerous polycyclic aromatic hydrocarbons.The mechanism was also discussed according to the results presented,particularly the deuterium-labeled and kinetic isotope effects experiments. |
